Bringing out the grain in curly maple

[MaineGeezer]

Does anyone have suggestions on how to best bring out the grain in curly maple?

[Danl8]

One approach can be an aquafortis stain, which is an old gunstock stain popular during the golden age of flintlock rifles. Made with rusty wrought iron and a strong acid (nitric). This is put on and heated to create the color. The effect is a rich brown to red brown stain that accentuates the figure of the curl. Another approach is potassium chromate dyes, and a good modern alternative water or alcohol-based analine dyes. You can also make a solution with ferric chloride which approximates aquafortis. All of these look awful until the varnish or drying oil goes on, when the color and figure explodes in depth, richness and color. One thing I don't do is fill the grain as it tends to reduce the depth effect.

[Mal-2]

One approach can be an aquafortis stain, which is an old gunstock stain popular during the golden age of flintlock rifles. Made with rusty wrought iron and a strong acid (nitric).

I think most people use steel wool now instead, as it is much easier to get (true wrought iron is fairly expensive) and the greater surface area makes the reaction go a lot faster. I do not know if it gives exactly the same results or not.

Here's an example, although his acid is not particularly strong. This might be another reason to prefer steel wool, to decrease the necessary acidity.

[Diane Kauffmds]

You can use a water based wood dye, in a nice dark brown or black. Mix the dye, and dye the maple. When dry, lightly sand it until you're satisfied with the color. The dye will penetrate the grain in the figure more than the unfigured wood.

I like Transtint, which is a very concentrated liquid dye.

Now I use dry aniline dyes. Keda makes a good product which is offered in a set of 5 colors, which is reasonably priced at ~ $15. The set comes with 3 primary colors, plus brown and black. They can be mixed into any color that you want.

I prefer water based dye, because once dry, it can be used under oil or water based finishes. Oil based stain can only be used under an oil finish.

[MaineGeezer]

Great suggestions, folks! Thanks.

[Danl8]

Oops, made an inexcusable chemist’s mistake. Ferric nitrate is the aquafortis shortcut. It’s easier than the steel wool method described above and provides a good result. Steve, having used all of these options, the one I would most recommend is water soluble analine dyes. Very easy to use and highly controllable in terms of color/tint.

[MaineGeezer]

I have no great desire to mess around with nitric acid. The aniline dye approach sounds as though it is more appropriate for my level of skill (or lack thereof). The neck blank is way oversize, so I will have plenty of extra wood to practice on....

[MaineGeezer]

Here is a photo of the latest attempt on a sample piece. It looks better in person than it does in the photo, but this gives the general idea. The photo doesn't capture the 3-dimensiona quality that one sees when actually looking at it.

This was finished, more or less, as: a coat of shellac, a wipe on/wipe off coat of Behlen brown maple stain, another coat of shellac, and a coat of Tru-Oil. Those were interspersed with steel wool and/or sandpaper rubdowns. It will need more Tru-Oil to get a smooth gloss.

[Diane Kauffmds]

It looks good.

[jbjewitt]

I cant help it - but I have to correct some of the above...…

Aquafortis is an old name for weak Nitric Acid HNO3
Ferric Nitrate is also know as Iron Nitrate Fe(NO3)3

The combination of Aquafortis and rusty iron no doubt was the old time version of what is also known in the old furniture industry as "Iron Buff" a stain that can also be made by soaking steel wool in white vinegar (acetic acid). The reaction products iron acetate which reacts with high-tannin woods like oak to product a chemical called ferric tannate which is a grey-black stain.

The way I have used Nitric Acid is to apply it (without the iron) and then heat the wood. On pine this products the elusive "Pumpkin Pine" look found on old Shaker furniture. The problem with Nitric Acid is that it "stays put" in the wood.

I have never heard of using Ferric Nitrate on wood. I think that reference should have been to Ferrous Sulphate which will produce a brownish-gray look.

Most of these metal salt chemical treatments depend on a rather high tannin content in the wood. Maple doesn't have a high tannin content so they are rarely effective (the exception being straight Nitric Acid)

I use dyes mixed with water. Here is a photo of a 00 maple body that was done by mixing TransTint Golden Brown at double strength, allowing to dry, then sanding back with 220. Then it was dyed again using the Golden Brown at normal strength. It has several coats of 2 part urethane.